RHA CL2 Planar

Intro:


I noticed a page on Head-Fi about an upcoming review tour being run by RHA for their new innovative planar magnetic IEM and was delighted to be offered a place.


My thanks to Colum and the rest of the team at RHA!


From an information page about this IEM:

RHA’s CL2 Planar is built around a revolutionary 10mm planar magnetic driver, usable for the first time in both wired and wireless configurations.

• Planar magnetic driver
• Detachable MMCX ceramic housings
• Supplied with 12-hour Bluetooth® neckband with aptX™ compatibility
• 3.5mm oxygen-free copper and balanced 2.5mm silver-coated cables
• Injection moulded ceramic housings
• Folding carry case, carry pouch, flight adapter and sports clip
• Supplied with dual density, double flange and Comply™ Foam ear tips

More information: rha-audio.com/cl2-planar


Appearance, packaging and contents:




The packaging and presentation here is absolutely top-class with a remarkably generous array of included extras.


The IEM came with two cables (as detailed above).

The first is their ‘standard’ cable; a pure copper cable sheathed in clear plastic with a 3.5mm single-ended (SE) plug.


The second is a cable with a 2.5mm balanced plug; I’m assuming from the description that it is silver-plated copper but do check on their website directly or on the threads for confirmation.


They are detachable and use the MMCX connectors and hence can be used with a huge variety of aftermarket cables. In other products I’ve reviewed, the 3.5mm cable is usually the poor, inbred cousin of the premium 2.5mm offering.

However, in this case, I have to say that whilst the 2.5mm is a quality cable, attractive and well made, both sonically and aesthetically, I greatly prefer the 3.5mm copper cable.

Whilst the earhooks are somewhat thicker than I would wish, the rest of the cable is fairly non-microphonic, sturdy without being heavy and looks gorgeous. If cables are your thing.

Aren’t they everybody’s thing? Perhaps that’s just me


The MMCX connectors are delightfully easy to attach and detach, without any perceivable looseness.


Ironically, the hardest part of cable swapping was not the MMCX connectors per se, but rather the IEM’s themselves, which are extremely small and with a very smooth polished finish.


Unusually, the CL2 even comes with a Bluetooth neckband, which is a generous addition at any price point. I am a tin-foil hat wearing Luddite, so I eschewed testing it, but I’m nevertheless delighted to see such an inclusion


For those of you who like to listen to IEM’s (well, listen to music onyour IEM’s to be precise!) in bed, these are the only IEM’s aside from the now extinct Trinity Audio Hyperions that I have found which fit into the ear without protruding out. I suspect that even ‘side-sleepers’ like myself would be able to use these comfortably, which for me is almost unheard of.


The sound:


I started out using my main DAP to play the music on for testing; the iBasso DX200 (with AMP8 and the new CB12s 4.4 cable).

However, I have a known sensitivity to certain sounds or aspects of treble.

Listening to the CL2 with the silver-plated cable, I found that on some songs I was wincing with too much treble. Switching to smaller, deeper inserting tips and using the copper cable with my DX120, all helped to pretty much eliminate these issues.

A few songs quickly helped me to draw out some of the prime characteristics of this IEM:


Fear – Blue October (Phil Tan Remix)(16/44 FLAC)

Immediate delights are found in the way that the CL2 portrays the pounding drums, but what crept up on me is the way that towards the end of the song, there were quite a lot of things going on (instrumentally speaking) and the CL2 has this marvellous ability to let each of them shine whilst binding them together in a cohesive whole.


The Obvious Child (and The Coast) – Paul Simon(HDTracks 24/96 FLAC)

I listened to The Obvious Child and then listened to ‘The Coast’, another track from the same album immediately afterwards. My impressions are related, so I shall put them both here.

What is highlighted here is just how well the CL2 handles percussion of all kinds. Timbre and decay are absolutely on point and the bassier percussion barks with the authority of a stentorian-voiced drill sergeant telling you to drop and give him 20.

Also, these songs both feature delicate shimmering guitar and other instruments, some more prominent, others only in the background of the mix. However, the CL2 really lets these shine; they seem more prominent and noticeable than with other IEM’s yet without losing any of their delicacy or shimmer (these qualities are magnified further).


When The World Was Young – Jimmy Page & Robert Plant(16/44 FLAC)

This one impresses right from the start. The song begins with (what I believe is) the plucking of a double bass with some delicate percussion layered over the top.

The timbre on both of these are excellent, very realistic and lifelike, and this quality continues as the vocals and electric guitar come in.


Summary:


Overall, I would describe the CL2 as being an outstanding IEM.


Let’s start with some caveats and the evolution of my impressions.

I am treble sensitive and found these IEM’s to trigger that initially.

I must stress, I am autistic and this is a known sensitivity that I have.

Even with this sensitivity, through playing around with cable, source, ear tips and so forth, I’ve been able to eliminate the issue.


If you know that you are unusually treble sensitive and are happy to try both the included cables (and any others you might have) and various eartips, then I believe you’ll be able to really enjoy these.


If you have such sensitivities and you only want something that works ‘straight out of the box’ with whatever eartips you usually use, then you might want to consider something smoother.


There are probably plenty of people for whom the CL2 will indeed work straight out of the box.


However, I think, more so than on other IEM’s I’ve heard, the CL2 are great rewarders of patience and experimentation. From simple and cheap things like trying different ear tips and playing with EQ (personally I found this wasn’t necessary for me, but some swear by it), to cable swapping and trying different sources or amps.


For me, moving from my DX200 DAP to the DX120, swapping from the included silver-coated cable to the included copper cable and changing from my usual Symbio hybrid tips to the included spherical foam tips actually made a huge difference. The warmer sound signature of the DX120 along with the other changes I made really took the edge off of the CL2 for me, but without compromising the many great aspects of its sound signature.


I would hesitate to describe it as a ‘one size fits all’ IEM, but that’s ok; at the TOTL level, it’s really a question of recognising that certain aspects of a sound signature are mutually exclusive to a certain degree. So, it’s all about finding the sound signature that works for you, and then choosing an IEM accordingly.


With this in mind, here’s the unique flavour that the CL2 brings to the mix:


It has a solid low end that doesn’t bleed into the mids. The signature is fairly linear relative to some of the more V-shaped IEM’s I’ve heard of late. However, there is a lift in the treble that really helps to open up the sound and give a boost to the feeling of spaciousness. There’s no area of the sound signature that I feel is lacking or recessed.


It has a deceptively large soundstage. When I first heard it, I was somewhat underwhelmed with this aspect. But changing tips and extended listening has disabused me of this misconception.

I sometimes noticed sounds that I’ve never heard before in familiar songs (for me, a hallmark of quality in an IEM, especially given that I’ve heard a fair few TOTL ones and have been playing the songs I love on high quality equipment for a good many years now).

I noticed these sounds, and in some cases, I realised I was becoming aware of them because they were presented outside what I had previously thought was the outer limit of the CL2’s soundstage!


A common theme in the songs I tested it with was that the CL2 has really excellent separation, imaging and placement. It repeatedly allowed each individual instrument and vocal in the songs to shine, but without ever compromising the marvellous sense of cohesiveness.


The CL2 has detail in spades, but it is still extremely cohesive. These qualities, combined with its accurate presentation of timbre, make this an IEM that lets you really enjoy the music.


Conclusion:


The CL2 is either the first, or one of the first, to bring planar magnetic technology to an IEM in a compact form (and bear in mind that I could say the same thing even if this were the size of a significantly larger IEM; the fact that it manages to implement planar magnetic technology with such expansiveness in such a tiny shell is nothing short of astonishing).


It offers an expansive soundstage and marvellous separation and layering; a high level of detail, accurate representation of timbre and a balanced sound signature with a beautiful cohesiveness.


I think this is a TOTL IEM. If you look at the price tag and conclude that it can’t ‘roll with the big boys’, then you would be making a mistake. Like all TOTL IEM’s what you’re looking for here is whether the sound signature on offer is the right fit for your tastes. If the CL2 sounds like it’s ticking all your boxes, then I encourage you to demo it and thank your lucky stars that they’re not charging £2k or more

Quick Read Conclusion

RHA have created an amazing “audiophile starter pack” with their CL2 IEMs (the “CL2s”). A stunning set of cables, APTx Bluetooth headset, carry cases and tips galore make the CL2 pack an excellent high-end entry into this hobby. The sound is, in the words of RHA themselves a little “marmite” (meaning you either love it or you hate it). The high mid/low treble spike created, in certain tracks, a sort of metallic/tinny tinge I did not enjoy. So then, a 4 overall – 5 as a package, but a high 3 for the sound signature of the CL2s themselves.

Introductions and General Bumf

This review of CL2s follows a familiar format. As intimated above, I have also gone into a little more detail than usual on the bundled accessories, as they were pretty good!

For the avoidance of doubt, I am in no way affiliated with CTM and have received no inducement from them to write this review.

Test Kit: I have tested the CL2s with a Samsung Note 8 and Galaxy S8 (using both UAPP and Tidal), an 11" Macbook Air (2012 vintage, running Tidal), an Astell and Kern AK70 mk 1 (both balanced and unbalanced), an iFi iDSD Nano Black Label, xDSD and also a Schiit Modi 2 Uber into a Vali 2 ("Schiit Stack").

Preparation: I received the CL2s as review samples and didn't give any additional burn in before any listening as I was reasonably far down the list of reviewers!

Me as a listener: I am not a pro by any stretch of the imagination. I have always enjoyed my music, and my tastes are pretty broad. I go to live music ranging from rock and pop concerts to orchestra and opera. I would not describe myself as having a trained ear, but I am attentive and my ears are in pretty good nick for a 36 year old.

My tastes: neutral to warm, but I do like good punchy bass and I love to hear decent instrument separation. As my experience broadens, my tastes are also extending into extended treble over very heady bass, especially where that treble extension helps to build soundstage, imaging and separation.

Test tracks: Test tracks noted in the review below were the TIDAL 16/44.1 available through their Hi-Fi subscription.

So, on to the main event. [/General Bumf]

Tech Specs

I have set out below the key technical specifications for the CL2s – I presume the quoted specs below are at 1kHz, but will ask RHA to confirm and update accordingly. I also note that, on writing this article, the CL2s are priced at £710 on Amazon.

Spec



I was excited to hear the CL2s. The thought of a planar magnetic earphone in a sensible IEM (looking at you Audeze with those spider web IEM monsters!) package is definitely exciting, especially if that planar fast bass was apparent.

Unboxing

You will see from the photos below that the unboxing experience is every bit as premium as the high price tag for the CL2s should demand. The box itself is a sort of “book” style box, made of premium card, and from which unfolds the main box itself. From left to right of the unfolded package are the cables and tips, the CL2s themselves and the Bluetooth headband, then a couple of carry cases (a soft pouch and a much harder magnetic latched case) and the various manuals and charging cable.



Accessories

Included in the box with both the CL2s are a 3.5mm terminated cable, 2.5mm terminated (balanced) cable, 2 carry cases, 3.5mm to 6.25mm adaptor, aeroplane adaptor, cleaning tool, silicon and foam tips (small, medium and large of each as well as some proper comply foam tips which are my personal favourite), 2 sets of double flange silicon tips and a warranty card and user guide. Some comments on a few of these are set out below.



Cables

At this price range it is great to see a couple of superb cables included. Microphonics from both are minimal. Both cables are twisted, with the 3.5mm presumably all copper and the 2.5mm looking like a silver plated copper cable. Both cables have some sheathed coiled metal wires like a spring, running back from the MMCX connectors to help retain shape. Both cables have premium, RHA branded terminations and chin sliders, giving a v expensive feel.



Tips

I was really pleased to see such a comprehensive set of tips, included Comply TSX-400 tips. I also found the metal plate that they were packaged felt premium and was a very helpful solution to how to package tips.

Bluetooth NeckBand

This was one of the “wow” items in the package. Whether or not you like the neckband format, including an APTx Bluetooth neckband with the CL2s was, in my opinion, a bit of a masterstroke. The neckband itself is rubberised black, with wires appearing with the bottom, terminating with mmcx connectors. As such, this headband can also be used with any suitably connected headphones/IEMs. The band itself has a USB-c charging input, and a small button set for power and volume.

Sound quality from the neckband was as good as I have heard from any similarly specced wireless DAC/Amps. Sure – this is not a competitor for very focused audiophile offerings like the iFi xDSD (lacking the detail, clarity, soundstage and definition of the xDSD in particular), but even so, SQ was perfectly acceptable especially if you are using IEMs on a journey where you are inevitable going to have a little background noise.

I swapped around between a few different IEMs, auditioning on my CA Polaris and SE425s. I couldn't find any stats for the neckband, but it comfortably pushed both of these IEMs with no interference or evidence of impedance issues.



Overall Thoughts

As an overall comment though, what RHA have done here, is include in one box literally everything you need to get going with this hobby. Great cables, lots of tips, a high quality Bluetooth headband and a thoroughly decent pair of IEMs is a solid gateway.

Practicalities

Glancing at the numbers above, the impedance figures for the CL2s are fairly low and they do change with different sources. Through a source with a suitably low impedance (like my AK70 mk 1 or iDSD Black Label), the CL2s sung. Plugged into my Lenovo ThinkPad X1 or Samsung phones however, the mid/low treble spike described below was accentuated. Although I don't know the output impedance of my laptop or phones, I suspect the “rule of 8” (headphone impedance should be at least 8x output impedance) is offended with a 15Ω IEM like the CL2.

I also didn't really get on with the harder shelled case included in the box. Personal preference/user error, but I found the cables fell out of it in my bag!

Fit and Tips

Despite cramming a planar magnetic driver in, the shells of the CL2s are actually pretty small – think a slightly bulbous Shure IEM, see pictures below. Consequently, I think these are IEMs that most people will find comfortable. In terms of tips, as mentioned before, RHA have gone all out supplying a full host of tips, including my favourite Comply tips.



The Sound

Highs, Mids and Lows

With the exception of a spike in the lower treble/upper mid (discussed below), the CL2s deliver an overall balanced and coherent sound. There is detail in the highs – percussive impact in Pearl Jam’s Go, clearly presented above the rapid bass – sometimes an area of confusion or congestion for lesser IEMs but the CL2s showed some of their planar talent here. To really test the bass speed on the CL2s, I threw Thundercat’s UhUh at them. For bass response look no further than this track – the speed with which note after note is pounded out of the bass guitar is often too much, even for otherwise brilliant performers, with a flabby “blurring” of notes demonstrating an inability to keep up with Thundercat’s flamboyance. Not so the CL2s, again demonstrating their talent for rapid response without losing any detail, every note clearly defined.

As indicated before however, there is a spike in the lower treble/upper mid-range, which on certain tracks can create a metallic, artificial quality to the music which I did not always enjoy. I particularly noticed this on acoustic guitar tracks – Oasis’ Married with Children taking on a tinny tinge, which made the otherwise bitter vocals feel a little thin. Move to the orchestral, and the effect was to bring to the fore the higher ranges of the string section particularly. In the right track this actually sounded brilliant – Spring from Vivaldi’s Four Seasons for example. However, in orchestral tracks involving the full breadth of the orchestra (think anything John Williams/Star Warsesque, especially where there should be depth in the brass section) and the effect of this spike is to suppress other sections of the orchestra.

I did not always dislike the CL2s sound signature, which actually brightened up a number of tracks. At times though, it made them a little fatiguing, and the metallic twinge I was hearing on acoustic guitar tracks (a personal favourite) means the CL2s are not at the top of my list for this price range.



Soundstage, Separation and Detail Retrieval

Unquestionably scaling with source, and significantly more detailed through the AK70 than their supplied Bluetooth headband, the CL2s demonstrated able performance across separation and detail retrieval. As mentioned above, I found that the CL2s were able to hold lucid instrument separation together on often challenging tracks where the CA Polaris cannot keep up. Soundstage was also good, with width and depth both on show. Nothing like the size, and lacking the height and holographic nature of a TOTL IEM like the CTM DaVinci X, the CL2s nevertheless convey more space than I have heard from an IEM this physically small.

Brief Comparisons

CA Polaris – a much more neutral tuning than the “V” shaped CA Polaris, the CL2s can’t match the visceral impact of the dynamic driver bass, but outperform on PrAT, especially where the bass is moving quickly.

UE900s – the CL2s outperform the UE900s across the board; delivering more soundstage, greater definition and gleaning more detail form the source materials.

CA FIBAE ME – in a similar story to the comparison with the CA Polaris, the CL2s don't quite have the bass impact of the FIBAE ME but their sense of timing, especially on busier passages, is superior. The FIBAE ME fly away from the CL2s though with detail retrieval, musicality, warmth and instrument texture.



Niggles

Other than a small issue with the hard case, and the “marmite” tuning (both discussed above) none!

Conclusion

The CL2s are a lovely little IEM with a stand out sense of rhythm and timing, sold in a superb value package with everything you need to get going with this hobby. To be fair, the tuning of the CL2s, in some ways, make them recommendable. They sound truly different to all other IEMs I have heard and, whilst I did not always enjoy their signature, it makes them a unique point of comparison.

The Scottish outfit, RHA, recently released a fully closed IEM that features a planar magnetic driver in it. While planar magnetic in-ear monitors and earphones are not new, there has never been one that has been made in this smaller form factor and fully closed.

The Audeze iSine series was a large unit that was worn as a hybrid between a clip-on headphone a la Koss KSC series and in-ear canal phones. They sound beautifully with the Cipher cable, Reveal plugin, or the right EQ, but sounded pretty wonky in it’s stock form.

The Unique Melody ME1 was released shortly after the original iSine 10 and 20 were released and featured a more traditional in-ear monitor style but with a large Audeze LCD series look. It was a fully open-back planar IEM like the iSine before it. It comes in both a Universal and Custom IEM option. I have owned the iSine 10 and the ME1 universal, and now own the ME1 custom.

More recently, two Chinese brands have come out with their own planar IEMs, the **** MT100 and the Toneking BL1. They both feature vents in them, and are not truly closed backs are are available for around $200 each. I have yet to hear either one of these.

And finally, the RHA CL2 at $899, was released.

RHA graciously sent out a set of these IEMs around the world as part of the Head-Fi Tour and I happened to miss the boat during the initial sign-up. After contacting RHA towards the end of the tour, they did not hesitate to allow me a chance to audition these, so I am very grateful for this opportunity to demo them and provide you my insights.

Build and Accessories


The RHA CL2 packaging comes packed with accessories, all of the highest quality. The first thing I discovered was the various variety of cables. The CL2 comes with a copper-colored standard 3.5mm cable with preformed hooks, as well as a silver-colored balanced 2.5mm cable with hooks. In addition to this is a neckband cable that converts the CL2 into a Bluetooth device. The Cl2 features mmcx connectors, so users can also use other cables with it as well.

A small selection of tips of various sizes is also included in the packaging, as well and product manual, airplane adaptor, and a usb cable for charging the Bluetooth neckband.

The CL2 features a hard ceramic shell that houses the single planar-magnetic driver. The closed shell has a shiny, glossy piano black finish and feels very solid and lightweight in the hand as well as in the ear. With about an hour of continuous playtime, I do sometimes start to feel a little ear pain on my left ear, but not as much on the right. This was a little surprising given the small size and good fit I was getting on initial placement.

For this review, I will focus mainly on using memory foam tips, but I also had lucky with SpinFit CP145 tipes. The Bluetooth cable and it’s quality are not part of this review, and I will be primarily discussing how it sounds based on 2.5mm balanced connections when available.

Sound
First off, the RHA CL2 requires a lot of power. Unlike many IEMs, these have very low sensitivity and require a bit of power output to drive them well. I used the Cl2 in combination with various sources including the Pioneer XDP-300R balanced Digital Audio Player and the Monolith THX-AAA balanced amp/DAC. I also used these with the Cavalli Liquid Spark and on some occasions, the Pete Millet Starving Student Tube Hybrid. Some times the source files came directly from my PC, the XDP-300R or the Hidizs AP80. In all cases, files were either CD-Rip FLACs or streaming through the highest quality Spotify or Tidal Hi-Res or Master quality.

My music selection was vastly varied throughout the time I listened with the CL2. My playlist stretches across most genres and my typical baseline album to listen to is Fleetwood Mac’s Rumours, as this showcases various instruments and 4 unique singers. I also tend to throw in the mix Chris Stapleton, Norah Jones, The Civil Wars, Tegan and Sara, Radiohead, Olafaur Arnalds, Daft Punk, The Roots, Vince Guaraldi, and various other artists and songs when demoing headphones.


First off, the CL2 is one of the fastest headphones I’ve had the pleasure of listening to. It’s not as fast as the Stax SR-009, but it’s faster than any of the planar magnetic headphones I’ve listened to and I own and have listened to quite a few. It’s also faster than the Focal dynamic driver headphones I have (The Elex and Elegia). In general, it makes the iSine 10 and Unique Melody ME1 sound slow with longer decay time. The transient speed is a bit ethereal in this sense.

While the bass response actually shows a little bit of a hump, the speed doesn’t allow the bass to bleed over at all. It’s very tight and controlled, and even sounds a tad lean due to its fast attack. When listening to it side-by-side with the ME1, the bass on the ME1 is weightier and meaner, despite it being rolled-off, but also sounds slower in comparison.

The mids is where the CL2 starts to fall apart a little bit. Male vocals sound natural and wonderful. Again the bass never bothers the mids, and the lean bass and mids are clean and almost analytical in a sense. It does sometimes needs a little more body, especially if you’re used listening to the Audeze LCD series or the HD6X0 from Sennheiser, or even the ME1. In a sense, the iSine 10/20 have this sort of leaner sounding mids, but the CL2 is even leaner. It is a type of sound I do enjoy though, as is the case in the Focal Elex I absolutely love.

The upper mids is where things start to get a little, well, weird. This is due to an abnormal rise in the upper mids that peaks up around 4KHz in the lower treble and then steeply drops down to 6KHz. Normally, I do enjoy a little bit or presence here, but the CL2 rises over 5-7dB more than I am used to in this region, and it’s an area, again, that I like boosted (see Hifiman HE560, Focal Elex, Tin Audio T2, KZ ZSN, etc as examples of headphones I gave good scores to and share a peak here).

This giant peak does a few things. First, it completely exaggerates string instruments and brings them front and center. It also makes cymbals splash more. In both cases, these sound unnaturally high and harsh. I love hearing the intricacies of guitar work, and that peak does help you hear every last detail, but it makes the timbre off and sound very unnatural. In addition, this peak makes the upper-mids and especially female vocals, sound veiled and compressed and, again, unnatural. I never enjoyed Norah Jones or Stevie Nicks, and Liz Fraser’s crazy voice sounds even crazier.

The rest of the upper treble range is also boosted, but does not suffer as badly with large peaks, though is still a tad uneven. The fast planar speed really helps level off this area though and gives it an electrostatic-type sound to it. Very fast and slightly artificial.

Conclusion

In comparison, the ME1 is quite dark sounding. The ME1 is a shade darker than Diffuse Field neutral, but in general hovers very closely to that sound profile, while can be at fault for a small bump around 1KHz which creates a tad of shouty sound. The CIEM version I have cleans that area up a little bit and it’s less bothersome, while generally evening out the upper mids and treble.

I found that while the ME1 has some unevenness in sound and is darker and richer than my typical preference, that is was much more coherent than the CL2, and that was really due to that large peak in the lower treble.

Luckily with a little bit of equalizer work, and bumping that region down 5dB or more, the CL2 starts to sound more normal, and helps fix some of its biggest flaws. Similarly, the ME1 can be fixed with some smaller adjustments in the raising the treble region a couple dB and raising the subbass up. The iSine can be fixed using the Cipher cable, Reveal Plugin, or some small tweaks using EQ.

What am I getting at? It seems every planar magnetic IEM has some flaws right now, but they benefit from very low distortion numbers and ability to eq to your needs. I think the Cl2 requires the most EQ work to correct it’s flaw, and I find it’s offering price a little high. The overall package is quite handsome and attractive with the nice cables and Bluetooth kit provided though.